A polymeric silver thiosaccarinate complex with a two-dimensional triply entangled mesh and argentophilic interactions

Abstract

Silver(I) complexes with sulfur-donor ligands have a broad range of pharmacological applications. One of the most important factors for tuning the biological activity is the type of donor atom and the ease of ligand replacement. Silver thiosaccharinates display a wide range of structures from mono- to polynuclear complexes. We report the synthesis, crystal structure and vibrational spectroscopic analysis of a two-dimensional Ag(I)-thiosaccharinate coordination polymer, namely poly[tris(μ2-4,4'-bipyridine-κ(2)N:N')bis(μ3-1,1-dioxo-1,2-benzisothiazole-3-thiolato-κ(3)N:S(3):S(3))bis(μ2-1,1-dioxo-1,2-benzisothiazole-3-thiolato-κ(2)S(3):S(3))tetrasilver(I)], [Ag2(C7H4NO2S2)2(C10H8N2)1.5]n, with 4,4'-bipyridine acting as a spacer. A relevant feature of the structure is the presence of an unusually short Ag...Ag separation of 2.8859 (10) Å, well within the range of argentophilic interactions and confirmed as such by Raman analysis of the low-frequency spectrum. From a topological point of view, the structure presents interpenetration in the form of a threefold entangled 2D→2D mesh (2D is two-dimensional).

Structure and electrical properties of a one-dimensional polymeric silver thiosaccharinate complex with argentophilic interactions

“…A CSD survey of reported AgÁ Á ÁAg distances in similar complexes disclosed that the 2.8307 (8) Å value in (I) is the second shortest found in silver thiosaccharinates, second only to the extremely effective centrosymmetric double bridge [ 2 -2 S:S] 2 = (SAg 2 S) present in XIHQUB (Dennehy et al, 2008) and leading to a value of 2.789 Å . The remaining short distances found involve either (i) a combination of the 2 -2 N:S bite on one side plus a 2 -2 S:S bridge on the other, as in EPUMUZ (Dennehy et al, 2016;d = 2.886 Å ), or (ii) plainly the same head-to-tail [Ag(tsac)] 2 dimers found in (I). As a comparison, the values in the already discussed topologically similar XIHREM (2.952 and 3.000 Å ), in spite of being within what is usually considered 'ligand-assisted' argentophilic interaction distances, are nonetheless significantly longer than the shortest distances found in (I), viz.…”

“…Among the former studies, some reports in the literature show that the AgÁ Á ÁAg stretching vibration may reveal the eventual presence (and strength) of a silver-silver interaction (Morishima et al, 2014;Harvey, 1996). We have evaluated argentophilic interactions by means of Raman spectroscopy in a previous work (Dennehy et al, 2016). The Raman spectrum of (I) (see Fig.…”

“…In addition, the EC of (I) is compared with those of some related polymeric silver thiosaccharinates, viz. [Ag 2 (tsac) 2 -(4,4 0 -bipyridine) 1.5 ] n , (II) (Dennehy et al, 2016), and [Ag-(tsac)(4-MeOpy)] n (4-MeOPy is 4 methoxypyridine), (III) (Dennehy et al, 2010), with the aim of explaining eventual EC differences in terms of their structural variations. riding, with aromatic C-H = 0.93 Å and U iso (H) = 1.2U eq (C), methylene C-H = 0.97 Å and U iso (H) = 1.2U eq (C), and methyl C-H = 0.96 Å and U iso (H) = 1.5U eq (C).…”

1D and 2D Silver-Based Coordination Polymers with Thiomorpholine-4-carbonitrile and Aromatic Polyoxoacids as Coligands: Structure, Photocatalysis, Photoluminescence, and TD-DFT Study

“…For the preparation of Ag-CPs, we used thiomorpholine-4-carbonitrile (L) and aromatic polyoxoacids as coligands (trimesic acid, H 3 BTC; pyromellitic acid, H 4 BTEC; 5-sulfosalicylic acid, H 3 5SSA; Figure ). L was chosen as a ligand since it belongs to the class of bis-monodentate ligands which are able to form Ag-CPs, − although it has never been used for this purpose. On the other hand, selected coligands showed photoluminescent properties − and can easily form Ag-CPs ,,,,− photoluminescent in some cases. − ,, …”